New Mode of Coordination for the Dinitrogen Ligand:  A Dinuclear Tantalum Complex with a Bridging N₂ Unit That Is Both Side-On and End-On

Dinitrogen activation by group 4 and group 5 metal complexes supported by phosphine-amido containing ligand manifolds

“…The N-N bond length is 1.319(4) Å, consistent with a strongly activated N 2 moiety assigned a formal N 2 4-oxidation state [63,65].…”

“…We extended this design feature into an acyclic tridentate ligand system by positioning a single phosphine donor between two formally anionic amido donors, which should also prevent phosphine dissociation. The synthesis of the NPN Si donor set is shown in Scheme 11 [63]. While our first studies of this NPN ligand system were with tantalum, the chemistry of this tridentate ligand with zirconium and titanium is presented first.…”

“…The reaction of TaMe reducing agents such as Na/Hg or KC 8 was an important breakthrough for our group [63,65].…”

Activation of Molecular Nitrogen: Coordination, Cleavage and Functionalization of N2 Mediated By Metal Complexes

“…Addition of an excess of LiBHEt 3 to {Nb( [77] It is suspected that the reaction proceeds through an Nb III (m-H) 2 Nb III dimer that binds and cleaves N 2 with the reductive elimination of H 2 , a process known to generate dinitrogen complexes. [46,47,78,79] [82] In this example, shown in Equation 15, N 2 has not only been cleaved, but also functionalized via incorporation into the macrocyclic ring. The formation of new N À P and N À Si bonds degrades the ligand, but shows that functionalization of coordinated nitrogen is possible in these cleavage processes.…”

Bio‐organometallic Approaches to Nitrogen Fixation Chemistry

“…There are a few exceptions to this statement. One of the more fascinating examples is an asymmetrically bridged ditantulum N 2 adduct [87], but the structure suggested for intermediate D of Fig. 3.11 and provided explicitly in Fig.…”